Research On Dual Polarized Phased Array Antenna Units And Array Antenna

Dual-polarized phased array antenna is an important part of the phased array radar system, which has the advantages of polarization agility, high sensitivity and strong anti-interference ability. Most of the ordinary dual-polarized antennas are realized using the same radiator which are fed by the orthogonal feed, to achieve the dual polarization. However these type of dual-polarized antennas have the disadvantages of the low design freedom and low isolation between two ports. The complementary antennas with the same antenna patterns and complementary electric field and magnetic field, can be use to design dual-polarized antenna. Based on the metal ring antenna and the slot ring antenna, four types of dual-polarized phased array antennas working in C band with complementary structure have been designed. The main contents of this paper are as follows:Firstly, this paper introduces the theories of the aperture radiation element,metal ring and slot ring. The metal ring- rectangular patch dual-polarized antenna and slot ring- electric vibrator dual polarized antenna are designed on the basis of the loop antenna and its equivalent complementary antenna. The simulation results show that the aforementioned antennas meet the requirements in bandwidth and cross-polarization, and the port isolation is below- 20 d B. The electric field is approximately orthogonal covering ± 40 o in j =0o plane and j =90o plane.Secondly, the antenna pattern and the isolation of the aforementioned antennas can’t fully meet the requirement. According to the theory that the metal ring and slot ring are complementary antenna, the metal ring-slot ring dual-polarized antenna is designed. The simulation results show that the bandwidth of the antenna and cross-polarization can’t meet the requirements, and the port isolation is below-29 d B. The metal ring is difficult to fix and miniaturize, and The electric field is approximately orthogonal covering ± 18 o in j =0o plane. The micro-strip ring-slot ring dual-polarized antenna is designed. The simulation results show that the antenna isolation is below- 35 d B. The antenna pattern beam width and gain are almost the same. The electric field is approximately orthogonal covering ± 80 o inj =0o plane and j =90o plane. The measured results and the simulated results are identical with each other, which verifies that the feasibility of the proposed thedual-polarized antenna.Finally, the uniform linear antenna array and uniform circular antenna array are simulated using the micro-strip ring-slot ring dual polarized antenna. The effect of mutual coupling between each antenna elements on antenna performance including S parameters and radiation pattern is researched. The scheme that using add cavity to reduce the array mutual coupling is proposed.